Pump, compressor, motor, or the like



July 24, 1951 F. w. McoMBlE PUMP, COMPRESSOR, MOTOR OR THE LIKE 6 Sheets-Shee't'l 1 Filed May l, 1946 lllllll fob l w.

July 24, 1951 F. w. MGcoMBlE 2,561,808

PUMP, COMPRESSOR, MOTOR OR THE LIKE Filed May 1, 1946 6 Sheets-Sheet 2 ATTORNEY July 24, 1951 F. w. MGCOMBIE 2,561,808

PUMP, COMPRESSOR, MOTOR OR THE LIKE Filed May l, 1946 6 Sheets-Sheet 31 July 24, 1951 F. W. MOCQMENEI 2,561,808,

PUMP, COMPRESSOR, MOTOR OR THE LIKE Filed May l, 1946 6 Sheets-Sheet 4 July 24, 1951 F. w. MCCOMBIE 2,551,808

PUMP, COMPRESSOR, MOTOR OR THE LIKE Filed May l, 1946 6 Sheets-Sheet 5 2q 7T Fig/Z July 24, 1951 F. w. MGCQMBIE PUMP, COMPRESSOR, MOTOR OR THE LIKE S Sheets-Sheet 6 Filed May l, 1946 Y l W7 Figa@ Patented July 24, 1951 UNITED STATES PATENT OFFICE `2,561,808 PUMP',v eoMPREssoR, Morton, on THE LIKE `lirederick Walter McCombie, Ashton-on-Mersey,

` Manchester, England,

Pumps t Compressors Lniited,'[ `eltham, England assgnor to Megator Application May `1, 1946, sensing, 666,363 In Great Britain Mayffl, 1945 v l 'ffllhis invention has for its object -to pro'videan improved Aina'chine which whenfdriven by an external source vof power can `serve as 'a pump for liquids, or `as 'a `'vacuum pump, 'blower or compresser for air or gases, or `when supplied with iluid under pressure can serve as a motor.

yllpump,compressor or motor according to the 'invention-comprises a hollow member the interior of which deilnes an expansion `or displacement chamber, an `eccentric rotatably mountedtherein engaging `the interior walls of said hollow member at two oppositely `disposed points on the periphery of said eccentric to Yprovide a `substantiaily fluid tight seal and by virtue of vits rotational 4movement within said hollow member giving riseto the desired displacement or expansion eilect, said hollow member being mounted for `reiprccating movement'in 'theplan'e of rotation of rsaid eccentric, and valve means controlling vthe new y'ci Af'fluid to and Afrom said chamber through `suitable inlet `and outlet ports.

'The apparatus may include a, single hollow member or a plurality `in which lattercase each chamber will centain an eccentric.

tors'ome applications ofthe invention, `particularly for use with gaseous fluids 'or' low :viscosity liquid fluids, a tightflt between each hollow rree'mber and its :'associated eccentric Vis advantageous lor eillcient operation. `According to a 4,preterred embodiment of the invention,` such `tightness `is obtained by arranging and operating the machine so that the hollow member is `contained within the pressure chamber `and thus envelopedby fluid under pressureand by 'constructing the :hollow member (which maybe 'made 'for example of rubber, plastics or metalor combinathereof)tv to `dimer'isio'ns suitably related to tbelastityfof the materials used-SD' as t0 fender the "hollow vlmember flexible or deformable `under dilference 'of pressure "between theinside and l A outside vof the h 'ollcvzw member. In any case the hollow member may be 'lined with rubber or si `lfil'ar resilient material so fas to `assist in `obtaining `aLtightseal.

Tightness between 'the `hollow vmember 'and `a f' guiding surfaceon the stationarypart of themavc :hine is obtained, in'cperaticn, by `the difference `in pressure between the pressure 'chamber'a'nd the suction chamber.V Before foperation, the lhollow member may be `retained by `resilient means i.

against said guiding surface to provide an initial Seel `:and to hold 'theh'cllow member in position for essembly and dismantling.

In order 'that' the v invention may be clearly understood and readily carried `vinto eiect the ln- 25 Claims. (CL 10S-5163) 2 vention Vis hereinafter described with reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional View taken vertically through 'the axis of an embodiment of the present `invention and `on `a` plane corresponding to line I-l oilFigure 2;

Figure 2 is a cross-section view talgen on line 2-2 v ofFlgure 1;

Figure 2a is a cross-sectionalview taken on line 2li-2a of Figure 2;

Figure 2b is a cross-sectional View taken `on line url Figure 3 is a section drawnto an enlarged scale vand on the Vlongitudinal centre line of rone of the hollow members used in the embodiment shcwnin Figures land 2; y

Figure 4 is a transverse section on the line IV-IV in Figure 3;

Figure 5 `is an end elevation partly in section, the vsection being taken on Vthe line 5-5 "in Fig# ure`3;

Figures 6 and 7 illustrate in section and Vfront elevation a modified formY of retaining mechansvmk.

Figure `8 is a longitudinal vertical section of an alternative form of hollow member; u

Figure 9 is an end elevation o f the same the retaining mechanism being removed;

Figures 10 and 11 'illustrate in section an `'alternative form of hollow member andeccentric in two working positions;

Figures l2 and 13 are sectional plan views of the same; l 4

,Figure 14 illustrates in section a further form gf. bellow member:

Figure -l5 is `a longitudinal vertical section of a double-*acting form of machine in accordance with the invention;

Figures `16 and 157 are alongitudinal section and transverse section respectively of the form ofhollow member employed in the construction shown in Figure l5;

Figure 18 illustrates diagrammatically the applicaticn vof -a machine in accordance with the invention to the receiver of a compressor.

Referringrst to Figures 1 and 2, the casing I forms the high pressure chamber of the machine andthe cover 2 *.fo'rms .the low pressure or `suction chamber, :a .partition wall 3 being interposed between 'the said casing and co'Ver'to separate the chambers. The pressure branch 4 is connected directly withi'the Vpressure chamber l while the suction branch 5 is connected Vwith the suction chamberby a duct y6' `which may beinte'gral with the casing l and which leads into the suction chamber via a port 6c in the partition wall 3.

The rotor consists of a shaft 'I carrying, for example, three eccentrics 3a, 8b, 8c angularly offset witl. respect to one another by 120 to give a more uniform delivery and torque, .each eccentric being diametrically surrounded by one of the hollow members 9a, 9b, 9c, respectively.

These hollow members bear against a partition plate Sia, at the inner surface of the partition wall 3, which thus serves as a guiding surface for the reciprocating movement of the hollow members which is imparted thereto by the eccentrics. Ports Iii, II, l2 and I3 are arranged in plate 3a of which, ports |53 and I2 coincide with openings Illa and |2a in the partition wall 3 and lead directly into the suction chamber inside the cover 2 while ports Ii and I3 lead, through ducts Ilot4 and |3a respectively in the partition wall 3, into the pressure chamber inside the casing I. -Brackets Ida, Mb are attached, by means o i bolts I5,'to\the partition wall 3 and offer guiding surfaces parallel land opposite to that of plate 3a. As will be seen more clearly from Figure 3, plungers I6 are guided in bushes yI'I inside the body *9 of each hollow member such as 9b, 'Figure 2. The inner end of each plunger I6 ismade hollow to house a coiled compression spring i8. 'Ihe whole arrangement forms a resilient retainer device holding the hollow member in contact with the guiding plate 3a, Figure 2.

The rotor shaft 'I is joui-nailed in bearings ld, |91), retained by covers 25a, 25h in housings Zta, D which in turn are attached to lantern brackets Zla, 2lb tted `into circular holes 22a, 22h of the body I, the diameterof `which holes exceeds the circumcircle of the three eccentrics to allow axial assembling and dismantling of the rotor and casing. Glands Qta, 23h are arranged at the innerends of the brackets Zia, 2|b respectivelyto tighten the passage of the shaft 'l from the in- L teriorkof casing l to the open air. Spray rings ,Z'llmilb, prevent any liquid which might have seepe'd through the packing of glands 23a, 23h from reaching the ball bearings ld, |317." The inner ball races `are retained on the shaft 'I by means 4of nuts'ita, 28?), and a pulley (orother driving member) 2i is keyed to one end of shaft 1. The operation of the machine as illustrated iin Figures l and 2 is as follows:

Supposing the machine is used as a pump, the pulley or driving member 21 is dri-ven by Aan ext'ernals'ource o'i'power, say an electric motor, and the rotor shaft 'I is rotated in its bearingsla, 1535;' The hollowy members are restrained from f moving Ain a horizontal direction by the guiding surfaces 3c and 'llimfilllx and consequently perform harmonic oscillations in a vertical direction, the phases of which are Ystaggered'according to thev angularv offset ofthe eccentrics with respect yto one another. The eccentric 8b is shown infFigu'r'eZ in its-lowest position. Assuming clockwise rotation, it is moving to the left, thus increasing the volume enclosed in hollow member 9b. Consequently liquid is drawn in, through ports lil and l2, from-the suction chamber 2, where it is replaced by liquid drawn in through duct 6 and port lia from the suction branch 5. et` the same time liquid is displaced by the eccentric 8b in the interior of the body l and forced to leave the pressure chamber through branch 4. I When the eccentric has completed its movement to the left of the position shown in Figure 2, y the hollow member has reached its central position (not shown) when the ports I0 and I2 are 4 closed by the adjacent portions of the hollow member, and the ports and i3 are about to be placed in communication with the interior of the hollow member.

On its way in a clockwise direction from its eX- treme left position towardsl the, extreme right position, the eccentric Bb displac'esliquidfrom the interior of the hollow member 3b, lthrough ports `I I, I3 and ducts I la, i3d into the pressure chamber, thus compensating forthe equal displacement of liquid during the same period from the pressure chamber into the open end of the displacement chamber on the other side of the eccentric.

Before operation, the hollow members were already held resiliently against the guiding surface of plate 3a by the reaction of the spring-loaded plungers IS against the retainer surfaces Illa and Illb. As soon as operation starts, the hollow members are pressed by the pressure dierence between the pressure chamber and the suction chamber 2 against the guiding surface, thus securing the required tightness.` YInsteadof arranging ports I3 for therconnection of the interior of each hollow member with. thepressure chamber I, the hollow member maybe arranged so as to overrun the edge of the guiding surface 3a and thus to establish *theA aforesaidcommunication during a portion of the reciprocating movement of the hollow member. y n y If the hollow members are made of such ma; terial and to such dimensions as to be flexible or deformable under the pressurev difference between outside and inside of the hollow members, the said pressure diiferenceforces the inner walls bof the hollow lchambers against the sides and the periphery of the eccentrics thus securing tightness there also. l v v v The plate 3a forming the guiding surface `for `the hollow member may be made adjustable from outsideby the operator or by an automatic governor, with respect to the hollow member and/or portion 3 so as to control the timing and/or amount of delivery or admission of fluid. Such adjustment mayfor elxample, be made by means ofua threaded spindle passing outl of the pres- Sure chamber through a gland, or by hydrauli; cally operated piston or plunger. v

In Figures 3,y 4 and 5 an embodiment of a holllow member is shown on a larger scale. y'Iheloody 9 of the hollowmember is moulded in one. 1li-elm -for example, from rubber. An insert '34, ,f or example, of light metal,'isfmoulded into'thefbody 9. A plate 35, preferably made from plastics, is attached to the insert 34 by means of threaded screws :iB-screwed into metal insets 3l devetailed intothe plate 35.

The rubber mouldedbody 9 gives the required exibility while the insert 34 gives thev walls o f the hollow member greater strength to resist the pressure difference between the outside and the inside. 'The plastic plate `35 ensures low friction and wear between thehollow membenandfth'e guidingsurface and the low specificfgrat'fity.` of the materials used for the reciprocal ,hollow member reduces the inertia forces. y

The open end of the hollow member is cutout at 3| to allow clearance for the rotor sfhaftjl` (Figures 2 and 3)L and chamfered or Ilaredat 38 to facilitate the assembly with the eccentric. The plungers I6, bushes I'I and springs ISare housed in recesses 39 of the body 9. l Y g Referring now to Figures 6 and '7,thehollo'w member is denoted 9 and the fixedretainer bracket is I4'. A slidable, retainer plate 4 0.; is

guided on the pins 4|, 42, which arefxedtofthe y bracket |4, andis pressed against the face of the hollow member 9 by a coiled compression :spring i. Referring toFiguresl'i and .9, thehollow mem- `ber 8"', which is made from resilient `orflexible materiaL'iits int'o the tapered interior of the slidable shell A'lll'. `Plungers IG are fitted into bores 39 of `said shell d and are pressed by coiled `compression springs liii against the 'fixed retainer brackets Ida, leb. Split pins 43 limit the movement of the plungers It' when the hollow member` is removed from between the guiding surface 3a and the retainer brackets Msc, Mb.. The tapered contact faces between the shell 45 and the hollow member 9 provide `a wedging effect for` securing a tight seal between the hollow `member 9" and the eccentric.

Referring now to Figures 10 to 13, the eccentric 8'-.hassa recess 2S on one side (or recesses onboth sides) and the hollow member 8x has a correspondingrecess (or recesses) 23 on its inner side wall, and clearance 3i) along the shaft l of the rotor. l l

. In :the .position shown in Figures 10 and .12 the recesses 23 and 29 `do not register and the clearances Stare closed by the side faces of the eccentric. The operation of the machine is then substantially the same as in the corresponding phase .of the `embodiment shown in Figures l and 2. When however the eccentric 8 reaches .the positionof Figures 11 and 13 the recesses 2S do regis ter, on the one hand with the recesses 2E! in the hollow member Qa, and on the otherv hand with the clearance so connecting the of the hollow member to the surrounding pressure chamber duringa `portion of the operating cycle determined as `desired by the relative positions of the recesses 2S and 29.

Alternatively the hollow member @c may be fitted` with vone or more automatic discharge valves which open when the pressure `in the hollow member exceeds the pressure in the pressure chamber. In the embodiment which is shown `by way of example in Figure 14, the valve :lll slides on 'a `guide Lii and `closing assisted by a spring 41. When the valve'is open, the fluid passes from the hollow member into the pressure chamber through the ports a, 45h. Instead of being fitted to the hollow member, as shown in Figure 14, the `valve maybe in the guiding surface `3a in such a position that it is connected to the inten rior of the hollow member by means of` a `port during the delivery period. The admission of Afluid to the hollow member may be controlled by asimilar automatic valve in conjunction with a portin the guiding surface or by the motion of the `displacement hollow member as already described.

The embodiment of Figures 10 to 13 and of Figure lerespectively 4are particularly suitable for the 4application of the .invention to `a compressor or vacuum pump as they permit compression of the fluid inside the hollow member before the .hollow member `is placed into com munication with the pressure chamber.`

In the embodiment of Figures l5 to 17 a double-act`ing arrangement is shown. 'Iwo parallel and opposing guiding surfaces 3d, 3b are arranged, in this embodiment for example in a horizontal position and are straddled at one end by a partition wall 3. `Ports lcd, l2d and Ich, |21) respectively, are `arranged `in the guiding plates 3b `to `connect the interior S9 of the hollow member with the suction chamber `2. It will be noted fthatthe location of the ports ltd,

12d differs from vthat of lthe `ports |012, |21) befY cause the two sets of ports come linto operation at different phases. Ports Hd, ld and llb,.|3b., respectively, in the guiding plates 3d,.3b connect the interior 9s cf the hollow member with the pressure chamber I, again at differentphases `of `the operating cycle. l l

Thehollow member consists of two halves .9d and .Se fitted into one another as shown morein `detail in Figures 16 and 17. The two halves .fit closely into one another `but are free to move relatively to one another in a direction normal to the reciprocating movement of `the hollow member as a whole. The inner sur-faces `.are `in contact with opposite points of the circumfer. ence of `the eccentric 8, the gaps. between the halves 9d and 9e beingstaggered at the interior of thehollow member with respect to the gen-` eral partition plane Vin the centre of the hollow member tol prevent the contact `points from. over.-A running these gaps. V

Plungers Hic' loaded by coiled compression springs l`8a maybe housed in recesses .39cm the halves 9d, 9e of the displacement chambers. The

.. springs ita bear against collars Hd, Ile which in turn abut against the ends of the recesses 39a, tending to `force the halves 9d, 9e apart,` i,l e. against the guiding surfaces 3d, 3b (Figure 15). When the hollow member is not held between the guiding surfaces, further separation of the halves l 9d, Sie `is limited by pins 18d, Ille inserted intothe (ifi plungers lila (Figure i6). Ascanbe seeum'ore clearly in Figures 16, 17, the two halves of 'the hollow member `are cutaway to vform an elongated slot 3l between them and so to give the required clearance for the shaft. The extensions 32e, 32d respectively of the twohalves penetrate into-correspondinT recesses of the opposite half and are enveloped at their sides adjacent tothe elongated slot 3l bylips 33d, 33e respectively, .t0 prevent the formation of gaps through which leakage from the hollow member could occur.

In operation the eccentric 8 alternatively enlarges and reduces the internal volume of the parts of the interior 99 facing the guiding 'surfaces 3d and 3b respectively. This displacement, in a vertical direction in the arrangement of Figure 15, is `accompanied by a horizontal harmonic `reciprocation of the hollow member with respect to the guiding surfaces 3d, 3b. Assuming clockwiserotation, the eccentric on its movement from its lowest position-as shown` in Figurev 1.5 into its highest position causes the `hollov/.mem-v ber to uncover the ports 10b, 12b in the `lower guiding surface 3b so as to admit iiuid from-the suction chamber 2 into the lower half of the interior 99; the ports lld and i3d in the upper guiding surface v3d are also uncovered topallow the ,efflux `of liquid from the upper half `ofthe interior into thesurrounding pressure chamber l.

vWhen returning in a clockwise direction from the uppermost position (not shown) torthe lowest position as shown in Figure 15, the `eccentriccar-V ries the hollow member to the right, thus un-` covering the suction ports Incl and l2cl on the top guiding surface 3d and the pressure ports Hlb and l3h on the bottom guiding surface 3b.

It will `be noted that Ythe edges of the guiding surfaces 3d, 3b are chamfered or ilared at 38 so that the whole unit consisting of the part 3 and the two guide plates 3d, 3b can readily be pushed sideways over the hollow member after the ltwo halves 9d, 9c of the chamber havebeen assembled over the eccentric 8. l l

The pressure of the surrounding pressure chamber penetrates into the outer portion'of the Vgapbetween the twohalves 9d, Se and acts also ori'gthe surface of lthe elongated slot 3| thus forcing the two halves against the resp-ective guiding surfaces 3d, 3b to ensure tightness in operation.

It is a characteristic of the machine that the casing I, Figures 1, 2 and 15 does not function as alcylinder, abutment orfsimilar working part but merely as a. container. It may therefore be advantageous in certain instances for the rotor, hollow member and guiding surface to be arranged within the tank or receiver into which uid is being delivered, thus dispensing with a casing for the machine, the functions of which are performed `by the walls of the tank or receiver. An example 0f this embodiment of the invention is shown in Figure 18 which'illustrates diagrammatically a construction particularly adapted for use as an air or gas compressor or as a combined liquid pump and air or gas compressor or as a pump delivering liquid into a receiver for storage under air or gaseous pressure. In such a construction the shaft of the rotor may pass through the walls of the tank or receiver by means of glands and the bearings for the rotor may be arranged internally as shown `If the machine is used vfor operation with gaseous uids, for example, as a compressor or vacuum pump, or as a pump delivering liquid into a receiver for storage under air or gaseous pressure, it may be advantageous to arrange it so that the working parts are Wholly or partly submerged in a liquid iluid for lubrication and sealing and for cooling the gaseous huid, the latter being drawn off from an opening in or stored in the .upper part of the casing or receiver so that the liquid fluid remains in the lower part of the casingor receiver. For example in the construc-` tion shown in Figure 18, the lower part of the container 44 may contain the working parts wholly or partly submerged in liquid, while the upper part acts as a receiver for the gaseous fluid. f

Although in the constructions hereinbeiore described the hollow member has a straight line reciprocating movement it is within the scope of the invention to so .construct the apparatus that the*l hollow member has an oscillatory or other movement along, for example, an arcuate or curved path and consequently the word reciprocating is used in a broad sense.

What I vclaim is: A

1. A "machine for use as a pump, compressor, blower ror motor, comprising a casing, a partition dividing said casing into high and low pressure chambers, communication openings respectively ior said high and low pressure chambers, an eccentric revolvably mounted in said casing, a hollow member slidably mounted in said casing against one surface of said partition and diametrically surrounding said eccentric to be reciprocated thereby over the surface of said partition, said member interiorly cooperating with said partition and the enclosed periphery of said eccentric to dene an expansion chamber, guide means for maintaining said hollow member in contactwith said partition during its reciprocal movement, and passage means connecting said expansion chamber with said high and low pressure chambers respectively and closable alter nately during the reciprocatory travel of said member to control the ow of working fluid therethrough.

2. A machine for use as a pump, compressor, blower or motor, comprising a casing, a partition dividing said casing into high and low pressure chambers, communication openings respectively for said high and low pressure chambers, an eccentric revolvably mounted in said casing, a hollow member slidably mounted in said casing against one surface of said partition and diametrically surrounding said eccentric to be reciprocated thereby over the surface of said par.- tition, said member interiorly cooperating with said partition and the enclosed periphery of said eccentric to define an expansion chamber, guide means for maintaining said hollow member in contact with said partition during its reciprocal movement, and passage means through said partition for connecting said expansion chamber with said high` and low pressure chambers respectively and closable alternately by said member during its reciprocatory travel to control the flow of working fluid therethrough, said eccentric and hollow member being mounted in said high pressure chamber and subject to the pressure thereinfor assisting in maintaining said member tightly against said partition to seal the connection therebetween.

3. A machine as dened in claim 2, wherein said hollow member is composed of iiexible material to be compressed around said eccentric by the pressure in said high pressure chamber.

4. A machine as dened in claim 3, wherein a rigid insert is embedded in the flexible material f forming said hollow member and includes a bearing plate for sliding on said partition.

5. A machine as dened in claim 2, wherein said hollow member is composed of elastic ma,- terial for snugly surrounding said eccentric and vto be compressed around said eccentric by the pressure in said high pressure chamber.

6. A machine as dened in claim 2, wherein said guide means are supported by means carried by said partition.

'1. A machine as deiined in claim 2, wherein the hollow member comprises port means open to said partition and cooperative with said passage means. i

8. A machine for use as a pump, compressor, blower or motor, comprising a casing,a partition dividing said casing into high and low pressure chambers, communication openings respectively for said high and low pressure chambers, an eccentric revolvably mounted in said high pressure chamber, a hollow member slidably mounted in said high pressure chamber against the surface of said partition and diametrically surrounding said eccentric to be reciprocated thereby over the surface of said partition, said member interiorly cooperating with said partition and the enclosed periphery of said eccentric to denne an expansion chamber, guide means in said high pressure chamber for maintaining said hollow memberin contact with said partition during its reciprocal movement, resilient means between said guide means and said hollow member for biasing said member into sealing engagement with said partition surface, and passage means through said partition for connecting said expansion chamber with said high and low pressure chambers respectively and closable alternately by said member during its reciprocatory travel to control the flow of working fluid therethrough.

9. A machine as defined in claim 8, wherein said resilient means comprises plungers movably mountedinlbores in said hollow member, and springsin said bores and biasing said: plungers against said guide means'.`

10. A machine for use as a pump', compressor, blower or fmotor, comprising acasing, a` partition dividing said casing into high' and low pressure chambers, communication openings respectively for said high and low pressure chambers, an eccentric revolvably lmounted in said high pressure chamber, a rectangular sleeve member slidably mounted in said high `pressure chamberiand diametrically surrounding said eccentric to be reciprocatedthereby, one end of said member abutting saidpartition lfor sliding over the surface of. said `partition and interiorly cooperating with said* partition and the enclosedperiphery of said eccentric to denne an expansion chamber, the other end of said member being open to `said high pressure chamber to expose said chamber `to the action of A'said eccentric, guide means in said high pressure.- chanlberv for maintaining said hollow member in contactI with said partition during its reciprocal movement, and passages through said partition for connecting` said expansion chamber with said highand low pressure chambers `12. A` machine as defined in claim 10, wherein said eccentric and sleeve member are positioned below the normal liquid level in said high pressure chamber to be sealed bythelliquid.

13.Atmachine for useiasaapump, compressor, blowenormotor, comprising a casing, a partition dividing said casing into high and low pressure chambers, communication openings respectively for said high and low pressure chambers, an eccentric revolvably mounted in said high pressure chamber, a hollow member slidably mounted in said high pressure chamber against the surface' of said partition and diametrically surrounding said eccentric to be reciprocated thereby over the surface of said partition, said member interiorly cooperating with said partition and the enclosed periphery of said eccentric to define an expansion chamber, guide means in said high pressure chamber for maintaining said hollow member in contact with said partition during its reciprocal movement, ports in said partition and respectively opened alternateli7 by said member during its reciprocatory travel to control the iiow oi working fluid therethrough, and ducts formed in said partition for connecting at least one of said ports with said high pressure chamber, with at least one port in direct communication with said low pressure chamber.

lli, A machine for use as a pump, compressor, blower or motor, comprising a casing having an opening, a partition closing said opening to deiine with said casing a high pressure chamber, a shell secured to said partition to denne therewith a low pressure chamber, communication openings respectively for said high and low pressure chambers, an eccentric revolvably mounted in said high pressure chamber, a hollow member slidably mounted in said high pressure chamber against the surface of said partition and diametrioally surrounding said eccentric to be reciprocated thereby over the surface of said partition, said member interiorly cooperating withsaid iartiticnand the enclosed periphery of said eccentric to define an eXpansionchamber, guide `means in Saidhigh pressurechamber for maintaining said hollow member in contact with said partition during `its reciprocal movement, and through said partition forV connecting said chamber with said high and low pressure chambers respectively and closable alternately by said member during its reciprocatory travel to control the lowof working iiuid therethrough.

15. A machine as denne-:l in claim lli, wherein said communication openings are formed in said casing, a port` in said partition, and a duct integral with said casing and connecting one of said` openings with said partition port to define the opening for said low pressure chamber.

161A machine for use as a pump, compressor, blower or motor, comp sing a casing having'an opening, a partition prall covering said opening to define with said casing a high pressure charnber, an opening through said partition wall, channels integral with said partition wall and protruding into thearea of said opening, a flat partition plate insertable` through said casing opening and mounted on the inner side voi said' partition wall to cooperate with said channels to denne ducts opening into said high pressure chamber, a cover mounted` on `saidpartition wall to define with `said wall a low pressure chamber, communication openings respectively for said high and low pressure chambers, an eccentric removably mounted in saidhigl'i` pressure chamber, a .hollow member L insertable through said casing opening and slidably mounted in` said high pressure chamber against the inner surface of said partition plate, said member` diametrically surrounding said. eccentric to be reciprocated thereby overthe surface ofsaid partiticn plate and. interiorly cooperatingV `with `said partition and the enclosed periphery of said eccentric to deiine an expansion chamber, guide means in said high pressure chamber for maintaining said hollow member in contact with said partition, plate during its reciprocal movement, and ports in said partition plate for connecting said expansion chamber with said low pressure chamber and with said ducts for communication with said high vpressure chamber and closable alternately by said member duringv its reciprocatcry travel to control the iiow ci working fluid therethrough.

17. A machine for use as a pump, compressor, blower or motor, comprising casing, a partition dividing said casing into high and low pressure chambers and including two spaced parallel guide plates, communication openings respectively for said high and low pressure chambers, an eccentric revolvably mounted in said casing and between said guide plates, a hollow member slidably mounted between said guide plates and in sealed contact with the surfaces thereof, said member diametrically surrounding said eccentric to be reciprocated thereby along the surfaces of said guide plates and `interiorly cooperating with said plates and the respectively opposite periphery portions of said eccentric to dene two separate expansion chambers, and passages through said guide plates and partition for connecting said expansion `chambers with said high and low pressure chambers respectively and clcsable alternately by said member during its reciprocatory travel to control the flow of working huid therethrough.

18. A machine as defined in claim 17, Wherein said hollow member is composed of two separable halves that are joined midway between the opposite sliding surfaces thereof.

19. A machine as defined in claim 18, whereinthe joint between said halves is staggered and includes extensions protruding perpendicularly to the mean line of said iointto pro- Yvide an overlap and permit separation of said halves, and spring means between said halves for biasing them apart and into sealing engagement with the respective guide plates.

20. A machine for use as a pump, compressor, blower or motor, comprising a casing, a partition dividing said casing into high and low pressure chambers, communication openings respectively for said high and low pressure chambers, a shaft rotatably mounted in said high pressure chamber, a plurality of spaced eccentrics iixed on said shaft, a plurality of hollow members slidably mounted in said high pressure chamber against; the surface of said partition, each of said members diametrically surrounding one of said eccentrics to be reciprocated thereby over the surface of said partition and interiorly cooperating with said partition and the enclosed periphery of said eccentric to define an expansion chamber, guide means in said high pressure chamber for maintaining saidrhollow members in contact with said partition during their reciprocal movement,

and passage means through said partition for connecting each of said expansion chambers with said high and low pressure chambers respectively and closable alternatelyby the respective member during its reciprooatory travel to control the iiow of working uid therethrough.

21. A machine as deiined in claim V'20, wherein said eccentrics are successively oset by uniform angles with respect to each other. i

22. A machine as defined in claim 20, wherein its reciprocatory travel, and a passage comprisingpassage portions in the sides of said eccentric and said member and which are cooperatively alignedduring an angle of revolution by said eccentric forl connection with the otherof said chambers.

. 25. A machine as deiined in claim 1 wherein said passage means includes a passage through said partition for connection with one of said chambers. and closable by said member during its reciprocatory travel, and a passage through'said member for connection with the other of said chambers, and a'pressure responsive valve; closing said member passage.

' FREDERICK WALTER MCCOMBIE.

REFERENCES' CITED The following references are of record in the nie of this patent:

UNITED STATES PATENTS Number Name Date 779,900 Bartlett Jan. 10, 1905 1,240,211 Horvath Sept. 18, 1917 FOREIGN PATENTS Number Country V Date France NOV. 30, 194.0 

